Optimising nearest neighbour information—a simple,efficient sampling strategy for forestry plot imputation using remotely sensed data

The rapid adoption of LiDAR-assisted forest inventory, together with nearest neighbour imputation, has created new challenges for those involved in sample selection. It is not obvious a priori what type of sample will be the most efficient when used with imputation. In this paper we explore a number of sampling approaches, including conventional methods such as stratification, spatial methods based on tessellations, and balanced sampling. We introduce a new approach called nearest centroid (NC) that optimises the survey design by using the distance properties of the sample in the space defined by the auxiliary variables, and examine this and other methods across a range of survey situations and objectives. The NC method is shown to be highly efficient when compared with other methods and is very flexible in the way it can be implemented.     

Resultados perinatales tras prueba diagnóstica invasiva en el embarazo

IntroductionInvasive prenatal diagnostic techniques allow us to conduct genetic tests. The development of non-invasive techniques has reduced their use. The foetal loss rate following an invasive procedure is considered to be around 1%. The published data is heterogeneous however, although everything indicates that the risk has been overestimated, we need to conduct further studies.Material and methodsIn our single-centre retrospective study we analysed the procedures carried out using invasive prenatal diagnostic techniques between 2011 and 2019. A total of 832 invasive techniques were performed. Perinatal results are compared with a control group of pregnant women (n = 1734).ResultsThe early foetal loss rate for the different techniques were 1.1% for amniocentesis, 1.6% for transvaginal chorionic biopsy and 5% for abdominal chorionic biopsy, with a total rate of 1.1%, without statistically significant differences between them (P = .57). We found differences in foetal outcome, in terms of variable early foetal loss, related to the attempts made (when three attempts were made, the risk increased). When comparing the perinatal outcomes after delivery of the group that underwent techniques with the control group, a higher rate of caesarean sections was found in the study group (28.9% vs 20.5%), in addition to lower mean gestational age at delivery (38.33 vs. 38.95 weeks).DiscussionWhen the invasive technique is performed at the right time and with no more than two attempts, we consider that the risk of foetal loss is not affected, and is equal to that of the general population.     

Managing the difficult case of fetal anemia

Objectives.?To describe a series of complex fetal anemia cases, detail the appropriate investigations and management, and review the literature.

Methods.?Four cases of non-red cell alloimmunization or infective cases of fetal anemia are presented.

Results.?Of the four cases presented, one was a neonatal death, one pregnancy was terminated, one case was diagnosed with Diamond Blackfan anemia, and one case was due to recurrent feto-maternal hemorrhages despite negative Kleihauer tests.

Conclusions.?Non-alloimmune causes of fetal anemia can be difficult to manage. Some cases require repeated and frequent intrauterine transfusions. The perinatal mortality and preterm delivery rates are increased, and some cases require considerable long-term treatment including regular transfusions. We present our experience of a series of non-immune fetal anemia managed in a tertiary unit, review the literature, and suggest appropriate management.     

Emotional reactivity to war stressors: An experience sampling study in people with and without different psychiatric diagnoses

There is a lack of knowledge regarding real-time emotional reactivity to high-intensity stressors, particularly in people with mental illness, a potentially vulnerable population. The current study aimed to examine negative emotional reactions to recurring high-intensity stressors within a continuous war situation, in people with different psychiatric diagnosis types. Experience sampling method was used to examine emotional reactions among 143 civilians exposed to rockets during the 2014 Israel–Gaza war, of them 18.2% with psychosis, 14.7% with anxiety or depression and 67.1% without mental illness. Participants reported exposure to rocket warning sirens and the levels of 10 negative emotions twice a day for 30 days. Negative emotional levels were higher on most emotions following high-intensity stressors (sirens), that is, emotional reactivity was demonstrated in real-time during war. Overall, no difference in reactivity was found among the three study groups. Moreover, people with anxiety/depression were less reactive than people without mental illness on sadness and being overwhelmed. The findings indicate similar and sometimes lower emotional reactivity to high-intensity stressors in people with mental illness compared to the general population. Nevertheless, people with mental illness seem to have significant emotional needs during war, to be addressed in prevention and intervention efforts.     

Measurement of salivary cortisol – effects of replacing polyester with cotton and switching antibody

Stable performance between‐runs are essential in longitudinal studies and when different studies are being compared. However, changes in analytical kits and laboratory material occur and have the potential to threaten analytical stability. In the present case, we examined how salivary cortisol measurements in our laboratory were affected by: 1) changes in the tampon material and 2) changes in the antibody of the analytical kit. In study 1, saliva from healthy subjects (n = 19) was split and spiked to Salivette^® polyester and cotton tampons, respectively, and treated as ordinary samples before being analysed for cortisol using a Spectria RIA kit for cortisol. In study 2, 68 anonymous saliva samples were analysed with the Spectria Cortisol RIA kit both before and after the manufacturer changed the antibody. The change from polyester to cotton tampons reduced the measured concentration of salivary cortisol by 62?%. A difference of 12?% between the two runs with different antibodies could not be attributed to differences in storage or in thawing and freezing of samples. To conclude, both a change in the material of the Salivette used for collecting saliva samples as well as a change of antibody in a kit can have a major impact on measurements, as illustrated here for concentrations of cortisol in saliva. It is therefore recommended always to check that the analysis stays in statistical control in one's own laboratory when changes are made, even if the manufacturer reports that the changes should have no effects.